Finished my two papers, they are pretty much ready to be sent off to the publishers tomorrow. I'm so excited and afraid to send my mind-babies off into to cold and unforgiving world of biological research. If you have been wondering why I haven't been responding to your messages THIS is why. It is a super big deal to be published as an undergraduate, and I wasn't going to take the opportunity lightly. I'm celebrating by going out on a 6 winery walk tomorrow
, then a whole lot of nooky, bubble baths, and chocolate covered strawberries with my guy
.
so Here is one of my mind-babies...remember, you much be cruel to be kind, I can take it
Just forgive formatting issues
Color Preference Trials for the Great Pond Snail: Lymnaea Stagnalis
Abstract
Trichobilharzia ocellata is a parasitic trematode that causes the infection in humans known as swimmers itch. T. ocellata could be controlled via the control of its intermediate host, the gastropod Lymnaea stagnalis. Color based traps could be created for L. stagnalis if color preference were known. Little information on L. stagnalis behavior exists. At the Turnbull National Wildlife Refuge 35 randomly selected L. stagnalis in the size range of 45-55mm were collected from a coulee. Color preference trial runs were conducted with 7 different colors in water from the coulee. The trial duration was 45 minutes, at which point, the number of snails in each color field were counted. A light meter was used to test LUX levels penetrating the colored materials in order to rule out a possible brightness preference. Between trials the trays were cleaned, the coulee water refreshed, and snails were replaced. Research statistics discovered the snails had a strong preference for purple with a secondary preference of green. There was no correlation between LUX level and color preference. These results could be used in L. stagnalis population control methods, collection for study, or continued behavioral studies.
Keywords: Lymnaea Stagnalis, Color Preference, Behavior
Introduction
The perception of light and animal interpretation of this information is of recurring interest in biology. An attraction to various colors has been observed in many creatures such as vertebrates: Ruby-throated Hummingbirds 12 , and invertebrates: the Heliconius butterflies9. A wide range of animals are able to differentiate color and react with specific behaviors. Lymnaea stagnalis, the great pond snail, has the ability to see color due to the presence of pigmented cells in their retinas2. We questioned if the ability to observe color also influences L. stagnalis behavior.
We used an experimental approach to determine if L. stagnalis shows a preference for any of the colors presented. Our objective was (1) Determine color preferences and aversions of L. stagnalis (2) Determine if there is an association between the color preference and the total light availability (LUX). We hypothesized that the snails would have a preference for the color green due to the color of their major food source (algae).
Lymnaea stagnalis resides in still or slow moving freshwater. They prefer muddy sand or crushed stone surfaces and feed on diatoms, aquatic plants and remaining tissue of other gastropods2. They are a typical representation of the lentic snail group exhibiting moderately amphibious lifestyles, although they have been observed visiting deeper water2. They have complex light sensing organs that can function in aquatic as well as terrestrial environments. This strategy allows L.stagnalis to escape perceived threats and seek temporary refuge above the waters surface without sacrificing vision 2. The pit retinas of L. stagnalis, are indicated by partitioned dorsal and ventral depressions, with each pit separated by crests (internal ridges)15. A pair of camera-like eyes under a specialized region of the integument are also used to perceive light15. The favored visual organs while in terrestrial environments are the photoreceptive cells located in the shallow dorsal pits; however, in aquatic environments the spherical lens of the camera like eyes is more effective. Their curved corneas turn the eyes into a powerful optical system due to the small refractive index difference6. It is known that L. stagnalis use their visual capabilities in some visually guided behavior, though it is not clear if they are exploiting the full potential of the visual information6.
Eastern Washington University Turnbull Laboratory's coule, Cheney Washington was the location from which we collected the L. stagnalis test subjects. A coule is an isolated pond carved into the basalt rock that was formed during the Missoula Floods3. The coule is 730 meters above sea level, located on basalt rock surrounded by Ponderosa Pine savannah. The study coule has a surface area of approximately 1 ha and is approximately 2 m deep.
Methods
We collected 35 L. stagnalis (within the size range of 45 to 55mm) haphazardly from the coulee. The size range was chosen to ensure a consistent age range within the cohort. Water collected from the coulee filled the 33 cm x 22cm x 6cm glass trays, this ensured the use of underwater vision, providing consistency in the results. Plastic sleeves of -red, green, blue, yellow, black, white, and purple covered opposing halves of each tray, with no gap in between. We conducted tests for all possible color combinations. Each sleeve completely surrounded its side of the tray, top, bottom and all sides. For each trial the subjects had a choice between two colors-. For each color combination seven replicates with five snails in each replicate, for a total of 35 snails. Trials lasted for 45 minutes giving the L. stagnalis time to move freely, after which we counted and logged the number of snails in each color field. We did not count the snails on the boundary between colors. To prevent overexertion the test subjects were
released and new-subjects captured periodically between tests. The same individual snails were used in multiple tests, which could have affected the independence of our results.
We attempted to eliminate other factors which may have an effect on the behavior of the snails. After the each trial we removed the subjects and - rinsed the trays with clean water to remove the mucus trails, so that they would not follow or avoid the trails of the previous snails. We placed the trays at various orientations, all on the same table top, to avoid confounding color with the effects of electromagnetic or gravitational inclinations of the snails13. We conducted all trials during the day as it has been shown that the number of pigment granules in L. stagnalis retinas declines at night2. Because some snails exhibit negative or positive phototaxis1 it was important to ensure that color was not confounded with the total light levels reaching the snails through the sleeves. We used an Extech light meter LT300 to test the amount of light penetrating through the plastic sleeves of each color.
We used a binomial probability test ( = 0.05) to asses preference within each color combination (Table 1). A binomial probability test calculated the statistics for each experiment. Our null hypothesis was that L. stagnalis had no color preference, resulting in a random distribution of snails in the trays.
Results
The binomial probability test showed eight of the tails resulted in no statistically significant preference. (Table 1.) Purple was most often preferred, while green was the second most preferred (Figure 1). All tests involving black resulted in statistically significant avoidance of black (Figure 2). We measured LUX values of the light penetration for each color and compared the results to color preference (Figure 3). There did not appear to be a correlation between LUX and preference. Blue and purple LUX values showed to be 171 and 171.5 LUX respectively (Figure 3). Blue was only preferred over black, while purple was preferred four times. This is evidence L. stagnalis uses color vision potential as cues for behavioral alteration.
Figure 1. Proportion of the two most often preferred colors
(green and purple) compared to other colors offered.
Figure 2. The proportion of least favored color
(black) as compared to other colors offered.
Figure 3. The averaged LUX value for all offered colors.
Discussion
The goal of this experiment was to determine if L.stagnalis had a preference to a particular color. The experiment produced unanticipated results. Though the color green was favored by the L. stagnalis as expected, the color purple was preferred by the highest proportion of snails. Hoagland7 found similar results in her study done on Chrysallida convexa, in which she studied the color of substrate C. convexa rested upon. C.convexa rested upon substrates colored brown, green and purple most often. Further investigation into why the snails tend towards purple, is warranted. Our information should only be considered applicable in aquatic environments, until more research is done on color preference in terrestrial environments. Future research may also explore preference in relation to the ultraviolet and infrared ranges, as the snails may be able to see past the visible spectrum of light10.
Color traps have been used to control and monitor organisms with known color preferences, such as the agricultural pests the leafhoppers, Limotettix vaccinii and Scaphytopius magdalensis14. Pectinophora gossypiella and Helicoverpa armigera, pest insects in cotton crops, are also controlled by color based traps4. The tendency of L. stagnalis to move towards purple provides the information needed for color based trap testing. Two reasons for controlling the L. stagnalis population. They are a host of the parasite Trichobilharzia ocellata11, which causes schistosome dermatitis in humans. They are also an invasive species in New Zealand8. Learning research laboratories that study L. stagnalis may also have applications for color preference and phototaxis knowledge1.
, then a whole lot of nooky, bubble baths, and chocolate covered strawberries with my guy.
so Here is one of my mind-babies...remember, you much be cruel to be kind, I can take it
Just forgive formatting issues
Color Preference Trials for the Great Pond Snail: Lymnaea Stagnalis
Abstract
Trichobilharzia ocellata is a parasitic trematode that causes the infection in humans known as swimmers itch. T. ocellata could be controlled via the control of its intermediate host, the gastropod Lymnaea stagnalis. Color based traps could be created for L. stagnalis if color preference were known. Little information on L. stagnalis behavior exists. At the Turnbull National Wildlife Refuge 35 randomly selected L. stagnalis in the size range of 45-55mm were collected from a coulee. Color preference trial runs were conducted with 7 different colors in water from the coulee. The trial duration was 45 minutes, at which point, the number of snails in each color field were counted. A light meter was used to test LUX levels penetrating the colored materials in order to rule out a possible brightness preference. Between trials the trays were cleaned, the coulee water refreshed, and snails were replaced. Research statistics discovered the snails had a strong preference for purple with a secondary preference of green. There was no correlation between LUX level and color preference. These results could be used in L. stagnalis population control methods, collection for study, or continued behavioral studies.
Keywords: Lymnaea Stagnalis, Color Preference, Behavior
Introduction
The perception of light and animal interpretation of this information is of recurring interest in biology. An attraction to various colors has been observed in many creatures such as vertebrates: Ruby-throated Hummingbirds 12 , and invertebrates: the Heliconius butterflies9. A wide range of animals are able to differentiate color and react with specific behaviors. Lymnaea stagnalis, the great pond snail, has the ability to see color due to the presence of pigmented cells in their retinas2. We questioned if the ability to observe color also influences L. stagnalis behavior.
We used an experimental approach to determine if L. stagnalis shows a preference for any of the colors presented. Our objective was (1) Determine color preferences and aversions of L. stagnalis (2) Determine if there is an association between the color preference and the total light availability (LUX). We hypothesized that the snails would have a preference for the color green due to the color of their major food source (algae).
Lymnaea stagnalis resides in still or slow moving freshwater. They prefer muddy sand or crushed stone surfaces and feed on diatoms, aquatic plants and remaining tissue of other gastropods2. They are a typical representation of the lentic snail group exhibiting moderately amphibious lifestyles, although they have been observed visiting deeper water2. They have complex light sensing organs that can function in aquatic as well as terrestrial environments. This strategy allows L.stagnalis to escape perceived threats and seek temporary refuge above the waters surface without sacrificing vision 2. The pit retinas of L. stagnalis, are indicated by partitioned dorsal and ventral depressions, with each pit separated by crests (internal ridges)15. A pair of camera-like eyes under a specialized region of the integument are also used to perceive light15. The favored visual organs while in terrestrial environments are the photoreceptive cells located in the shallow dorsal pits; however, in aquatic environments the spherical lens of the camera like eyes is more effective. Their curved corneas turn the eyes into a powerful optical system due to the small refractive index difference6. It is known that L. stagnalis use their visual capabilities in some visually guided behavior, though it is not clear if they are exploiting the full potential of the visual information6.
Eastern Washington University Turnbull Laboratory's coule, Cheney Washington was the location from which we collected the L. stagnalis test subjects. A coule is an isolated pond carved into the basalt rock that was formed during the Missoula Floods3. The coule is 730 meters above sea level, located on basalt rock surrounded by Ponderosa Pine savannah. The study coule has a surface area of approximately 1 ha and is approximately 2 m deep.
Methods
We collected 35 L. stagnalis (within the size range of 45 to 55mm) haphazardly from the coulee. The size range was chosen to ensure a consistent age range within the cohort. Water collected from the coulee filled the 33 cm x 22cm x 6cm glass trays, this ensured the use of underwater vision, providing consistency in the results. Plastic sleeves of -red, green, blue, yellow, black, white, and purple covered opposing halves of each tray, with no gap in between. We conducted tests for all possible color combinations. Each sleeve completely surrounded its side of the tray, top, bottom and all sides. For each trial the subjects had a choice between two colors-. For each color combination seven replicates with five snails in each replicate, for a total of 35 snails. Trials lasted for 45 minutes giving the L. stagnalis time to move freely, after which we counted and logged the number of snails in each color field. We did not count the snails on the boundary between colors. To prevent overexertion the test subjects were
released and new-subjects captured periodically between tests. The same individual snails were used in multiple tests, which could have affected the independence of our results.
We attempted to eliminate other factors which may have an effect on the behavior of the snails. After the each trial we removed the subjects and - rinsed the trays with clean water to remove the mucus trails, so that they would not follow or avoid the trails of the previous snails. We placed the trays at various orientations, all on the same table top, to avoid confounding color with the effects of electromagnetic or gravitational inclinations of the snails13. We conducted all trials during the day as it has been shown that the number of pigment granules in L. stagnalis retinas declines at night2. Because some snails exhibit negative or positive phototaxis1 it was important to ensure that color was not confounded with the total light levels reaching the snails through the sleeves. We used an Extech light meter LT300 to test the amount of light penetrating through the plastic sleeves of each color.
We used a binomial probability test ( = 0.05) to asses preference within each color combination (Table 1). A binomial probability test calculated the statistics for each experiment. Our null hypothesis was that L. stagnalis had no color preference, resulting in a random distribution of snails in the trays.
Results
The binomial probability test showed eight of the tails resulted in no statistically significant preference. (Table 1.) Purple was most often preferred, while green was the second most preferred (Figure 1). All tests involving black resulted in statistically significant avoidance of black (Figure 2). We measured LUX values of the light penetration for each color and compared the results to color preference (Figure 3). There did not appear to be a correlation between LUX and preference. Blue and purple LUX values showed to be 171 and 171.5 LUX respectively (Figure 3). Blue was only preferred over black, while purple was preferred four times. This is evidence L. stagnalis uses color vision potential as cues for behavioral alteration.
Figure 1. Proportion of the two most often preferred colors
(green and purple) compared to other colors offered.
Figure 2. The proportion of least favored color
(black) as compared to other colors offered.
Figure 3. The averaged LUX value for all offered colors.
Discussion
The goal of this experiment was to determine if L.stagnalis had a preference to a particular color. The experiment produced unanticipated results. Though the color green was favored by the L. stagnalis as expected, the color purple was preferred by the highest proportion of snails. Hoagland7 found similar results in her study done on Chrysallida convexa, in which she studied the color of substrate C. convexa rested upon. C.convexa rested upon substrates colored brown, green and purple most often. Further investigation into why the snails tend towards purple, is warranted. Our information should only be considered applicable in aquatic environments, until more research is done on color preference in terrestrial environments. Future research may also explore preference in relation to the ultraviolet and infrared ranges, as the snails may be able to see past the visible spectrum of light10.
Color traps have been used to control and monitor organisms with known color preferences, such as the agricultural pests the leafhoppers, Limotettix vaccinii and Scaphytopius magdalensis14. Pectinophora gossypiella and Helicoverpa armigera, pest insects in cotton crops, are also controlled by color based traps4. The tendency of L. stagnalis to move towards purple provides the information needed for color based trap testing. Two reasons for controlling the L. stagnalis population. They are a host of the parasite Trichobilharzia ocellata11, which causes schistosome dermatitis in humans. They are also an invasive species in New Zealand8. Learning research laboratories that study L. stagnalis may also have applications for color preference and phototaxis knowledge1.
tadkil:
Good work. I would have eladmwithnthe invasive species issue in New Zealand. Other than that, thumbs up